CVE-2015-2855 in SSL Visibility Appliance
Summary
by MITRE
The WebUI component in Blue Coat SSL Visibility Appliance SV800, SV1800, SV2800, and SV3800 3.6.x through 3.8.x before 3.8.4 does not set the secure flag for the administrator's cookie in an https session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an http session, a different vulnerability than CVE-2015-4138.
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Analysis
by VulDB Data Team • 11/06/2024
The vulnerability identified as CVE-2015-2855 affects the WebUI component of Blue Coat SSL Visibility Appliance models SV800, SV1800, SV2800, and SV3800 running firmware versions 3.6.x through 3.8.x before 3.8.4. This security flaw represents a critical weakness in the appliance's session management implementation that directly impacts the confidentiality and integrity of administrative access. The vulnerability specifically concerns the improper handling of session cookies within the web interface, creating an avenue for man-in-the-middle attacks and credential interception. The issue stems from the appliance's failure to properly configure the secure flag on administrative cookies, which should be mandatory for HTTPS sessions to prevent cookie transmission over unencrypted channels.
The technical implementation flaw manifests in the WebUI's cookie creation process where the secure flag is omitted from administrator session cookies even when the connection is established over HTTPS. This misconfiguration allows attackers to capture administrative cookies during transmission, particularly when users navigate between HTTP and HTTPS sessions or when network traffic is intercepted. The vulnerability creates a path for attackers to escalate privileges and gain unauthorized administrative access to the appliance, potentially leading to complete system compromise. The secure flag serves as a critical HTTP cookie attribute that instructs browsers to only transmit cookies over secure HTTPS connections, and its absence represents a direct violation of secure web application design principles. This flaw operates independently from CVE-2015-4138, indicating a distinct vulnerability in the cookie handling mechanism rather than a broader authentication system weakness.
The operational impact of this vulnerability extends beyond simple credential theft to encompass complete system compromise and unauthorized access to sensitive network traffic data that the SSL Visibility appliance is designed to monitor and analyze. Attackers can exploit this weakness to intercept administrative sessions, potentially gaining access to network traffic decryption keys, configuration settings, and monitoring data that would otherwise remain protected. The vulnerability is particularly dangerous because it affects the administrative interface that controls critical network security functions, making it a prime target for attackers seeking to undermine the appliance's security posture. Organizations relying on these appliances for SSL traffic inspection and monitoring face significant risk of data breaches and network compromise when this vulnerability remains unpatched. The attack vector is relatively straightforward, requiring only network interception capabilities to capture the improperly configured cookies and establish unauthorized administrative sessions.
Mitigation strategies for CVE-2015-2855 should prioritize immediate firmware updates to version 3.8.4 or later, which addresses the cookie secure flag configuration issue. Organizations should also implement network segmentation and monitoring to detect potential cookie interception attempts, while ensuring that all administrative access occurs exclusively over encrypted channels. Security teams should conduct thorough vulnerability assessments of their SSL visibility infrastructure to identify any other improperly configured cookies or session management elements. The remediation process should include verification that administrative cookies are properly configured with the secure flag and that session management follows industry best practices as outlined in owasp secure coding guidelines. Additionally, network administrators should implement strict access controls and monitoring for administrative interfaces, as the vulnerability creates a persistent risk for any organization that fails to update their appliances to patched versions. This vulnerability aligns with CWE-614, which addresses the improper storage of sensitive information in cookies, and represents a significant concern for organizations operating network security infrastructure that requires strong administrative access controls and session management security.